The CT machine according to the existing technology generally is provided with a rotatable scanning frame, of which the inside wall is mounted with an X-ray tube and a detector corresponding to the X-ray tube. By rotating the scanning frame, the projection data of a human body can be acquired in all directions. This X-ray CT machine can acquire X-ray projection data from a human body in all directions by rotating the ray source, thereby reconstructing the projection data to form a tomographic image.
In order to obtain a high-quality tomographic image in a short time, two types of advanced CT machines are provided below at present.
1. CT Machine with Multiple Tubes:
In this CT machine, multiple X-ray tubes and multiple detectors are arranged on one same plane inside the scanning frame, thus the multiple tubes can emit rays simultaneously and the multiple detectors can receive projection data in all directions simultaneously; therefore, both the rotating angle of the scanning frame and the scanning time can be reduced. However, there are certain drawbacks existing in this type of CT machine. Due to the limited thickness of the conventional single-slice linear detector, tomographic image of human body with finite thickness can be acquired only each time, and there are severe limitations in acquiring dynamic images, such as heart images.
2. CT Machine with Multi-Slice Detector:
In order to solve the problem of slice thickness, multi-slice spiral CT appears in recent years. The multi-slice spiral CT technology has made a great breakthrough in the design of detector array, the selection of slice thickness, the reconstruction of algorithm and the improvement of scanning speed, and at present spiral CT machines with 8-slice, 16-slice, 32-slice and 64-slice image have appeared. However, the top number reaches 128 slices only. How to obtain bigger slice thickness remains a problem.
Since the above two CT machines are limited by the pixel size of the array unit of the detector, it is very difficult to achieve a higher spatial resolution, worse, the conversion rate of ray is low and the radiation dose is strong. In addition, existing CT machines are huge in size and are immovable, and the person who accepts physical examination must go to the fixed CT room, thus the usage is limited and the construction of CT room adds the cost to certain extent.
At present, no solution has been proposed in view of the problem existing in related art that the CT machine can not image in real time and is low in imaging efficiency and high in production cost.